Air turbo-refrigeration unit, method for operating same, and turbo-expander

ABSTRACT

The invention relates to refrigeration technology and can be used in air conditioning systems, refrigerators, etc. An air turbo-refrigeration unit comprises a compressor disposed on the same shaft as a turbo-expander, an electric motor, a two-cavity heat exchanger, a recuperator, a water trap, and a refrigeration chamber with a cooler and a fan. The unit Is equipped with a two-cavity heat exchanger/cooler, and with a second water trap and a third water trap; the compressor is connected by its outlet to the first cavity of the heat exchanger, which is connected to the first cavity of the heat exchanger/cooler, and the first cavity of the heat exchanger/cooler is connected via the second water trap to the first cavity of the recuperator, which communicates with the inlet of the turbo-expander via the first water trap; the turbo-expander is connected by its outlet via the third water trap to the second cavity of the heat exchange r/cooler, which is communicated with the cooler and is communicated via the cooler with the second cavity of the recuperator, which is communicated with the compressor inlet. The invention makes it possible to prevent the formation of ice and frost on the inner cavities of the turbo-expander and of ducts, which, in turn, prevents shut-off of the air turbo-refrigeration unit and increases the refrigeration capacity of the unit.

RANGE OF APPLICATION

The invention falls into the category of refrigerating equipment and maybe used in air conditioning systems, refrigerators, etc.

BACKGROUND OF THE INVENTION

A refrigerating plant is known which contains a compressor connected viaa heat exchanger with a centrifugal expander, and a supplementarypressure blower directly coupled to the centrifugal expander andinstalled between the heat exchanger and the refrigerating chamber (seeInventor's certificate SU No. 802740, Class F25B 11/00, published on 7Feb. 1981).

This plant requires a heat exchanger cooling system, since temperatureof the compressor outlet air is sufficiently high (about 120-140° C.)which increases total power consumption of the refrigerating plant.Besides, water vapor in air may result in freezing of passages of thenozzle and working arrays in the turbo-refrigerator.

The most close to this invention in technical essence and achievedresults as to a device as a subject of the invention is an airturbo-refrigerating plant which contains a compressor installed directlycoupled to a centrifugal expander, electric motor with the shaft coupledto the shaft of the compressor and centrifugal expander, double-cavityheat exchanger, recuperator, moisture separator, centrifugal expander,refrigerating chamber with a cooler and a blower, where inlet and outletof the second cavity of the double-cavity heat exchanger open to theatmosphere, besides inlet is via a blower, and the compressor inletopens via a valve member to the atmosphere (see patent RU No. 2156929,Class F25B 11/00, published on 27 Sep. 2000).

The same patent discloses a centrifugal expander containing acentrifugal expander wheel and a compressor wheel that are installed onthe same shaft installed in the shell within gas-dynamic bearings, and aprinciple of operation of an air turbo-refrigerating plant, the saidprinciple involving supply of compressed air into the first cavity ofthe double-cavity heat exchanger where compressed air is cooled withambient air fed by the blower via the second cavity of the double-cavityheat exchanger, following which compressed air is cooled in therecuperator with cold air supplied from the cooler of the refrigeratingchamber, then compressed air is separated from moisture in the moistureseparator and dried compressed air is sent to the centrifugal expanderwhere it is cooled by way of expansion and conversion of its pressureenergy into mechanical energy of rotation of the wheels of thecentrifugal expander and air compressor and then is fed under reducedpressure into the cooler of the refrigerating chamber in order to removeheat from, and cool the latter; from the chiller the air heated there isfed to the second cavity of the recuperator where compressed air iscooled and additionally heated air is fed from the recuperator to thecompressor inlet.

However, this plant and its principle of operation do not ensurerequired performance reliability due to the fact that because ofleakages in connections between tubes and heat exchangers, or duringloss of sealing of the closed coolant circulation system of the heatexchanger humid air may penetrate from the atmosphere into the closedcoolant circulation system of the heat exchanger, resulting in formationof ice and rime frost in inner cavities of centrifugal expander elementsand pipework. As a result it leads to decrease in cooling capacity orshutdown of the air turbo-refrigerating plant (ATRP).

INVENTION SUMMARY

The object of the invention is remedial of defects and deficienciesfound.

The technical result is that it becomes possible to prevent formation ofice and rime frost in inner cavities of the components of thecentrifugal expander and pipework which, in turn, helps to preventshutdown of air turbo-refrigerating plant and increase its coolingcapacity.

For air turbo-refrigerating plant, the technical result according to thefirst invention embodiment is achieved since the air turbo-refrigeratingplant contains a compressor directly coupled to the centrifugalexpander; electric motor with its shaft connected to the aircompressor/centrifugal expander shaft; double-cavity heat exchanger;recuperator; moisture separator; refrigerating chamber with a chillerand blower where inlet and outlet of the second cavity of thedouble-cavity heat exchanger open to the atmosphere where the latter'soutlet is via the blower, and the air compressor inlet opens via valvemember to the atmosphere, and the plant is equipped with thedouble-cavity heat-exchanging chiller, and the second and third moistureseparators, where the air compressor is connected with its outlet to thefirst cavity of the double-cavity heat exchanger, the said first cavitybeing connected to the first cavity of the double-cavity heat-exchangingchiller, the said first cavity connected via the second moistureseparator to the first cavity of the recuperator, the latter cavityconnected via the first moisture separator to the centrifugal expanderinlet, while the centrifugal expander is connected with its outlet viathe third moisture separator to the second cavity of the double-cavityheat-exchanging chiller, where this second cavity is connected to thechiller in the refrigerating chamber—and via the latter chiller—to thesecond cavity of the recuperator which is connect to the compressorinlet.

The plant may be equipped with an air drying package which opens viawith its inlet to the atmosphere, and with its outlet via the secondvalve member to the compressor inlet.

The double-cavity heat exchanger may be equipped with Peltierthermoelectric modules.

According to the second embodiment, the technical result is achievedowing to the fact that an air turbo-refrigerating plant contains acompressor directly coupled to a centrifugal expander, double-cavityheat exchanger, recuperator, moisture separator, refrigerating chamberwith a chiller and a blower, with the inlet and outlet of the secondcavity of the double-cavity heat-exchanger opening to the atmosphere,with the outlet being via the blower, and the plant is equipped with adouble-cavity heat-exchanging chiller, and the second and third moistureseparators, the second motor-driven air compressor, and the seconddouble-cavity heat exchanger, with the compressor connected via outletto the first cavity of the double-cavity heat-exchanger, the said firstcavity connected to the first cavity of the heat-exchanging chiller,connected in turn via the second moisture separator to the first cavityof the recuperator connected via the first moisture separator to theinlet of the centrifugal expander, while the latter is connected via thethird moisture separator to the second cavity of the heat-exchangingchiller, while this second cavity is connected to the cooler of therefrigerating chamber and—via the latter—to the second cavity of therecuperator, with this second cavity connected to the inlet of thesecond compressor, where this compressor opens with its inlet via thevalve member to the atmosphere and with its outlet, via the first cavityof the double-cavity heat exchanger connected to the compressor inlet,while the inlet and outlet of the second cavity of the seconddouble-cavity heat exchanger opens to the atmosphere, while the outletis via the second blower.

The plant may be equipped with an air drying package which opens withits inlet to the atmosphere, and with its outlet via the second valvemember is connected to the inlet of the second compressor.

The plant may be equipped with the second electric motor, the shaft ofwhich is connected to the shaft of the compressor and centrifugalexpander.

The double-cavity heat exchanger may be equipped with Peltierthermoelectric modules.

According to the third embodiment variant, the technical result isachieved because of the fact that the air turbo-refrigerating plantcontains a compressor directly coupled to a centrifugal expander, and adouble-cavity heat exchanger, recuperator, moisture separator and arefrigerating chamber with a chiller and blower, with inlet and outletof the second cavity of the double-cavity heat exchanger opening to theatmosphere, with the inlet via a blower, while the plant is equippedwith a double-cavity heat-exchanging chiller, the second and thirdmoisture separators, and the second and third compressors mounted on oneand the same shaft, electric motor, the shaft of which is connected tothe shaft of the second and third compressors, and the seconddouble-cavity heat-exchanger, with the compressor's outlet connected tothe inlet of the second compressor which is connected with its outletvia the first cavity of the second double-cavity heat exchanger to theinlet of the third compressor, whose outlet is connected via the firstcavity of the double-cavity heat exchanger to the first cavity of theheat exchanger connected via the second moisture separator to the firstcavity of the recuperator connected via the second moisture separator tothe inlet of the centrifugal expander, while the latter is connected viathe third moisture separator to the second cavity of the heat-exchangingchiller connected to the cooler in the refrigerating chamber and via thelatter to the second chamber of the recuperator, which is connected tothe outlet of the compressor, with the compressor outlet also openingvia the valve member to the atmosphere, while the second cavity of thesecond double-cavity heat exchanger opens at the inlet and the outlet ofthe atmosphere, however, at the inlet via the second blower.

The plant may be furnished with an air dryer package which via inletopens to the atmosphere and with its outlet via the second valve memberconnects to the compressor inlet, while the first and seconddouble-cavity heat exchangers are furnished with Peltier thermoelectricmodules.

The Plant may be equipped with the second electric motor the shaft ofwhich is connected to the shaft of the compressor and centrifugalexpander.

Another subject of the invention is a centrifugal expander as a part ofthe installations described above. The centrifugal expander is composedof wheels of the centrifugal expander and compressor mounted on thecommon shaft within a shell between gas-dynamic bearings, besides theshell contains an axial shaft stabilizer in the form of a compressorwheel installed in the shell opposite to the shaft end clear of the laststationary magnet.

An electric magnet may be installed as a fixed magnet in the axial shaftstabilizer.

In the axial shaft stabilizer a permanent magnet may be installed as astationary magnet.

The centrifugal expander may additionally contain a permanent magnetinstalled on the shaft end opposite to the stationary magnet.

The centrifugal expander may be equipped with the second axial shaftstabilizer made in the form of the second stationary magnet installed inthe shell opposite to the shaft end from the side of the centrifugalexpander wheel, with the second permanent magnet installed on the shaftend opposite to the second magnet.

In the second axial shaft stabilizer, an electric magnet may beinstalled as a stationary magnet.

The electric magnet may contain an electromagnetic field strengthregulator.

In the second axial shaft stabilizer, a permanent magnet may beinstalled as a stationary magnet.

As to the method as a subject of the invention, the claimed technicalresult is achieved owing to the fact that the principle of operation ofthe air turbo-refrigerating plant in any of Claims 1-3 involves supplyof compressed air with the compressor into the first cavity of thedouble-cavity heat exchanger in which compressed air is cooled withambient air fed by the blower via the second cavity of the double-cavityheat exchanger, then compressed air is cooled in the recuperator withcold air supplied from the cooler of the refrigerating chamber, afterwhich compressed air is separated from moisture in the moistureseparator and dried compressed air is fed to the centrifugal expander,where it is cooled by way of expansion and transformation of itspressure energy into mechanical energy of rotation of wheels of thecentrifugal expander and compressor and fed under reduced pressure tothe cooler of the refrigerating chamber in order to remove heat from andcool the chamber; from the chiller the air heated there is sent to thesecond cavity of the recuperator where compressed air is cooled, and airheated repeatedly is fed from the recuperator to the compressor inlet,with compressed air, before being fed into the first recuperator cavity,is cooled in the double-cavity heat-exchanging chiller with air suppliedvia the double-cavity heat-exchanging chiller from the centrifugalexpander, and separated from moisture in the second moisture separator,with the air cooled in the centrifugal expander, before being fed viathe double-cavity heat-exchanging chiller into the refrigerating chamberchiller, separated from moisture in the third moisture separator, whiletemperature in the refrigerating chamber and cooling capacity of the airturbo-refrigerating plant is regulated by changing rotation speed of theblower in the double-cavity heat exchanger.

Temperature in the refrigerating chamber may additionally regulated bycontrolling rotation speed of the air cooling blower.

Temperature in the refrigerating chamber may additionally regulated byadditional cooling of compressed air in the double-cavity heat exchangerby installing Peltier thermoelectric modules in the double-cavity heatexchanger.

Temperature in the refrigerating chamber may additionally regulated byadditional cooling of compressed air in the double-cavity heat exchangerby feeding water through the double-cavity heat exchanger.

Temperature in the refrigerating chamber may additionally regulated bychanging rotation speed of the electric motor, the shaft of which isconnected to the compressor/centrifugal expander shaft.

According to the second embodiment, the technical result may be achievedin the principle of operation of an air turbo-refrigerating plantperformed according to any of Claims 4-7, and this principle ofoperation of the air turbo-refrigerating plant includes supply ofcompressed air by the compressor into the first cavity of thedouble-cavity heat exchanger in which compressed air is cooled withambient air supplied by the blower via the second cavity of thedouble-cavity heat exchanger, then compressed air is cooled in therecuperator with cold air from the cooler of the refrigerating chamber,following which compressed air is separated from moisture in themoisture separator and dried compressed air is fed into the centrifugalexpander where it is cooled by way of expansion and transformation ofits pressure energy into mechanical energy of rotating wheels of thecentrifugal expander and compressor and fed at reduced pressure into thecooler of the refrigerating chamber for heat removal from the latter andcooling, from the chiller air is fed into the second cavity of therecuperator where compressed air is cooled, where compressed air, beforebeing fed into the first cavity of the recuperator, is cooled in thedouble-cavity heat-exchanging chiller with air fed into it from thecentrifugal expander and is separated from moisture in the secondmoisture separator, from air cooled in the centrifugal expander beforebeing fed via the double-cavity heat-exchanging chiller into the coolerof the refrigerating chamber, moisture is separated in the thirdmoisture separator, and then from the second recuperator cavity air isfed into the inlet of the second compressor which compresses air andfeeds it into the first cavity of the second double-cavityheat-exchanging chiller; in the latter, compressed air is cooled byfeeding ambient air through the second cavity of the double-cavity heatexchanger with the second blower, and from the first cavity of thesecond double-cavity heat exchanger air is fed into the compressor,while temperature in the refrigerating chamber and cooling performanceof the air turbo-refrigerating plant is regulated by changing rotationspeed of the blower of the double-cavity heat exchanger.

Temperature in the refrigerating chamber may be additionally regulatedby controlling rotation speed of the blower in the second double-cavityheat exchanger.

Temperature in the refrigerating chamber may be additionally regulatedby regulating of rotation speed of the electric motor of the secondcompressor.

Temperature in the refrigerating chamber and cooling performance of therefrigerating plant may be additionally regulated by simultaneouslyadjusting the rotation speed of the electric motor of the secondcompressor and adjusting the rotation sped of the blower of the seconddouble-cavity heat exchanger and the chiller blower. Temperature in therefrigerating chamber may be additionally regulated by additionalcooling of the second double-cavity heat exchanger using Peltierthermoelectric modules.

Temperature in the refrigerating chamber may be additionally regulatedby additional simultaneous cooling of the first and second double-cavityheat exchangers with Peltier thermoelectric modules.

Temperature in the refrigerating chamber may be additionally regulatedby additional cooling of the second double-cavity heat exchanger withwater.

Temperature in the refrigerating chamber may be additionally regulatedby additional simultaneous cooling of the first and second double-cavityheat exchangers with water.

Temperature in the refrigerating chamber may be additionally regulatedby regulating the rotation speed of the chiller blower.

Temperature in the refrigerating chamber may be additionally regulatedby regulating rotation speed of the second electric motor, the shaft ofwhich is connected to the shaft on which the compressor and thecentrifugal expander are mounted.

According to the third embodiment variant, the technical result may beachieved in the principle of operation of an air turbo-refrigeratingplant performed according to Claims 8-11, while this principle ofoperation of the air turbo-refrigerating plant involves supply ofcompressed air into the first cavity of the double-cavity heatexchanger, in which compressed air is cooled with ambient air fed by theblower via the second cavity of the double-cavity heat exchanger, thencompressed air is cooled in the recuperator with cooled air from therefrigerating chamber cooler, following which compressed air isseparated from moisture in the moisture separator and dried compressedair is fed into the centrifugal expander, where it is cooled by way ofexpansion and transformation of its pressure energy into mechanicalenergy of rotation of wheels of centrifugal expander and compressor, andfed under reduced pressure into the cooler of the refrigerating chamberfor heat removal from, and cooling of the said chamber, then from thecooler air is fed into the second cavity of the recuperator wherecompressed air is cooled, with this compressed air, prior to beingsupplied into the first cavity of the recuperator, is cooled in thedouble-cavity heat exchanging chiller with air fed via this chiller fromthe centrifugal expander, and is separated from moisture in the secondmoisture separator; the air cooled in the centrifugal expander, prior tobe fed via the double-cavity heat exchanging chiller into the cooler ofthe refrigerating chamber, is separated from moisture in the thirdmoisture separator; air from the second cavity of the recuperator is fedto the inlet of the compressor which compresses air and delivers it intothe second compressor, from where additionally compressed air is fed inthe first cavity of the second double-cavity heat exchanger wherecompressed air is cooled by ambient air fed with the second blower viathe second cavity of the double-cavity heat exchanger, while from thefirst cavity of the second double-cavity heat exchanger air is fed intothe third compressor, from which compressed air is fed into the firstcavity of the double-cavity heat exchanger, while temperature in therefrigerating chamber and cooling performance of the airturbo-refrigerating plant is regulated by adjusting rotation speed ofthe blower of the double-cavity heat exchanger.

Additional regulation of the temperature in the refrigerating chambermay be performed by regulation of rotation speed of the blower whichfeeds air in the refrigerating chamber via the blower.

Temperature in the refrigerating chamber may be additionally regulatedby additional cooling of compressed air in the double-cavity heatexchanger by installing Peltier thermoelectric modules in thedouble-cavity heat exchanger.

Temperature in the refrigerating chamber may be additionally regulatedby additional cooling of compressed air in the double-cavity heatexchanger with water. Temperature in the refrigerating chamber and itscooling capacity may be additionally regulated by regulation of rotationspeed of the electric motor, the shaft of which is coupled to the shaftof the second and third compressors.

Temperature and cooling performance in the refrigerating chamber may beadditionally regulated by changing regulation of rotation speed of thesecond electric motor, the shaft of which is coupled to the shaft of thecompressor and centrifugal expander.

As was found in the course of the experiment, pressure of working air inthe system downstream of the first compressor and, particularly,downstream of the second compressor increases considerably, since theelectric motor creates additional moment on the compressor shaft andincreases its power capacity. The heat-exchanging chiller installeddownstream of the compressors in the system ensures the deeper drying ofair. It can be seen from the formula:

d=0.622^(Ps/(P−Ps));

kg/kg where d, kg/kg—the absolute moisture content (kg of water per kgof dry air); Ps—saturated vapor pressure; P—air pressure.

Thus, as air pressure P increases, absolute moisture content ddecreases, which enhances air drying level. Moreover, the second andthird moisture separators allow to enhance drying efficiency, and theaxial stabilizer of the centrifugal expander shaft made in the form ofstationary permanent magnets and/or electric magnets on shaft ends ofthe centrifugal expander ensure stable operation of the refrigeratingplant and maintains nominal refrigerating capacity.

SHORT DESCRIPTION OF DRAWINGS

FIG. 1 presents the basic diagram of the air turbo-refrigerating plantin its first embodiment variant.

FIG. 2 presents the basic diagram of the air turbo-refrigerating plantin its second embodiment variant.

FIG. 3 presents the basic diagram of the air turbo-refrigerating plantin its second embodiment variant with the second electric motorinstalled.

FIG. 4 presents the basic diagram of the air turbo-refrigerating plantin its third embodiment variant.

FIG. 5 presents the longitudinal section of the centrifugal expander ofthe air turbo-refrigerating plant.

FIG. 6 presents the longitudinal section of the centrifugal expander ofthe air turbo-refrigerating plant with the second axial shaftstabilizer.

PREFERRED EMBODIMENT OF THE INVENTION

The air turbo-refrigerating plant designed according to patent claim 1(see FIG. 1) contains the compressor 1 mounted on the same shafttogether with the centrifugal expander 2, electric motor 3, the shaft ofwhich is connected to the shaft of the compressor 1 and centrifugalexpander 2, double-cavity heat exchanger 4, recuperator 5, moistureseparator 6, refrigerating chamber 7 with the chiller 8 and the blower9.

The inlet and outlet of the second cavity of the double-cavity heatexchanger 4 open to the atmosphere, while the inlet of the double-cavityheat exchanger via the blower 19, and the compressor 1 with its inletvia the valve member 11, open to the atmosphere.

The plant is equipped with the double-cavity heat-exchanging chiller 12,and the second 13 and third 14 moisture separators.

The compressor 1 is connected with its outlet to the first cavity of thedouble-cavity heat exchanger 4 with the latter connected to the firstdouble-cavity heat-exchanging chiller 12 connected via the secondmoisture separator 13 to the first cavity of the recuperator 5 connectedvia the first moisture separator 6 to the inlet of the centrifugalexpander 2, while the latter with its outlet via the third moistureseparator 14 is connected to the second cavity of the double-cavityheat-exchanging chiller 12, with the above second cavity connected tothe chiller 8 and via the latter—to the second cavity of the recuperator5, with the above second cavity connected to the inlet of the compressor1. The plant may be furnished with the air dryer package 15 which opensvia its inlet to the atmosphere, and with its outlet via the secondvalve member 16—to the inlet of the compressor 1.

The double-cavity heat exchanger 4 may be furnished with Peltierthermoelectric modules (not shown in the drawing).

According to the second design version (see FIGS. 2 and 3), the airturbo-refrigerating plant contains the compressor 1 directly coupledwith the centrifugal expander 2, double-cavity heat exchanger 4,recuperator 5, moisture separator 6, refrigerating chamber 7 with thechiller 8 and the blower 9.

The inlet and outlet of the second cavity of the double-cavity heatexchanger 4 open to the atmosphere, while its outlet is via the blower10.

The plant is furnished with the double-cavity heat-exchanging chiller12, and the second 13 and third 14 moisture separators, secondcompressor 17 driven by the electric motor 18 and second double-cavityheat exchanger 19, where the compressor 1 is connected with its outletto the first cavity of the double-cavity heat exchanger 4, the abovefirst cavity connected to the first cavity of the heat-exchangingchiller 12 connected via the second moisture separator 13 to the firstcavity of the recuperator 5, with the above first cavity connected viathe first moisture separator 6 to the inlet of the centrifugal expander2, while the latter is connected with its outlet via the third moistureseparator 14 to the second cavity of the heat-exchanging chiller 12,with the above second cavity connected to the chiller 8 and via thelatter—to the second cavity of the recuperator 5, the above secondcavity connected to the outlet of the second compressor 17, while thelatter opens with its inlet via the valve member 11 to the atmosphere,and with its outlet via the first cavity of the second double-cavityheat exchanger 19 is connected to the inlet of the compressor 1, whilethe inlet and outlet of the second cavity of the second double-cavityheat exchanger 19 open to the atmosphere, while its inlet is via thesecond blower 20.

The plant may be furnished with the air dryer package 15 which opens viaits inlet to the atmosphere, and via its outlet and the second valvemember 16 to the outlet of the second compressor 17.

The plant may be equipped with the second electric motor 2, the shaft ofwhich is coupled with the shaft of the compressor 1 and the centrifugalexpander 2. The double-cavity heat exchanger 4 is equipped with Peltierthermoelectric modules (not shown in the drawings).

According to the Third Embodiment (see FIG. 4)

The air turbo-refrigerating plant contains directly coupled compressor 1and centrifugal expander 2, double-cavity heat exchanger 4, recuperator5, moisture separator 6 and refrigerating chamber 7 with cooler 8 andblower 8.

The inlet and outlet of the second cavity of the double-cavity heatexchanger 4 open to the atmosphere, while its inlet is via the blower10.

The plant is equipped with the double-cavity heat-exchanging chiller 12,the second 13 and third 14 moisture separators, and the directly coupledsecond 17 and third 22 compressors, electric motor 28, with its shaftcoupled with the shaft of the second 17 and third 22 compressors, andthe second double-cavity heat exchanger 19.

The compressor 1 is connected to the inlet of the second compressor 17which is connected with its outlet via the first cavity of the seconddouble-cavity heat exchanger 19 to the inlet of the third compressor 22,whose outlet is connected via the first cavity of the double-cavity heatexchanger 4 to the first cavity of the heat-exchanging chiller 12, thesaid first cavity connected via the second moisture separator 12 to thefirst cavity of the recuperator 5, the said first cavity connected viathe first moisture separator 6 with the inlet of the centrifugalexpander 2, while the latter is connected with its outlet via the thirdmoisture separator 14 to the second cavity of the heat-exchangingchiller 12, the above second cavity being connected to the chiller 8 andvia the latter to the second cavity of the recuperator 5, the abovesecond cavity being connected to the inlet of the compressor 1, with thesaid compressor's inlet also opening via the valve member 11 to theatmosphere, while the second cavity of the second double-cavity heatexchanger 19 opening with the inlet and outlet to the atmosphere, and atthe inlet via the second blower 20.

The plant may be equipped with the air dryer package 15 which opens viaits inlet to the atmosphere, and through its outlet via the second valvemember 16 to the inlet of the compressor 1, while the first 4 and thesecond 19 double-cavity heat exchangers are equipped with Peltierthermoelectric modules (not shown in the drawing). The plant may beequipped with the second electric motor 21 the shaft of which coupled tothe shaft of the compressor 1 and centrifugal expander 2.

The centrifugal expander 2 which forms a part of the above describedplants (see FIG. 5), contains wheels 23 and 24 of the centrifugalexpander 2 and the compressor 1 directly coupled on the shaft installedin the shell 25 within gas-dynamic bearings 26, where in the shell 25the axial stabilizer 27 of the shaft 28 is installed in the forminstalled in the shell 25 opposite to the end of the shaft 28 on theside of the wheel 24 of the compressor 1 with a clearance relative tothe last stationary magnet 29.

In the axial stabilizer 27 of the shaft 28, an electric magnet may beinstalled as a stationary magnet 29.

The electric magnet may contain a magnetic field strength regulator (notshown).

In the axial stabilizer 27 of the shaft 28, a permanent magnet may beinstalled as a stationary magnet.

The centrifugal expander 2 may additionally contain a permanent magnet20 (see FIG. 6) mounted on the end of the shaft 28 opposite to thestationary magnet 29.

The centrifugal expander 2 may be equipped with the second axialstabilizer 31 of the shaft 28 in the form of the centrifugal 2 installedin the shell 25 opposite to the end of the shaft 28 on the side of thewheel 23 with a clearance relative to the latter with the secondstationary magnet 32, while the second permanent magnet 33 is installedon the end of the shaft 28 opposite to the second stationary magnet 32.

In the second axial stabilizer 31 of the shaft 28, an electric magnetmay be installed as a stationary magnet 32.

The electric magnet may contain its magnetic field strength regulator(not shown).

In the second axial stabilizer 31 of the shaft 28 a permanent magnet maybe installed as the stationary magnet 32.

The principle of operation of the air turbo-refrigerating plantaccording to FIGS. 1 and 5 is implemented as follows. Compressed air isfed with the compressor 1 into the first cavity of the double-cavityheat exchanger 4, in which compressed air is cooled with ambient airsupplied by the blower 10 via the second cavity of the double-cavityheat exchanger 4.

Then compressed air is cooled in the first cavity of the double-cavityheat-exchanging chiller 12 with the air fed through the said firstcavity from the centrifugal expander 2 and then is separated frommoisture in the second moisture separator 13.

Next compressed air is cooled in the recuperator 5 with cold air fromthe chiller 8 of the refrigerating chamber 7, following which compressedair is separated from moisture in the moisture separator 6, and driedcompressed air is fed into the centrifugal expander 2 where driedcompressed air is cooled and simultaneously depressurized, by way ofexpansion and transformation of its pressure energy into mechanicalenergy of rotation of the wheels 24 and 23 of the centrifugal expander 2and the compressor 1, respectively, following which the air cooled inthe centrifugal expander 2 is separated from moisture in the thirdmoisture separator 14 and fed at low pressure via the second cavity ofthe double-cavity heat-exchanging chiller 12 into the chiller 8 of therefrigerating chamber 7 in order to withdraw heat from, and cool, thisrefrigerating chamber.

From the chiller 8, air is fed into the second cavity of the recuperator5 where compressed air is cooled and then fed into the centrifugalexpander 2, and then air is fed from the recuperator 5 to the inlet ofthe compressor 1.

Regulation of temperature in the refrigerating chamber 7 and coolingcapacity of the air turbo-refrigerating plant is performed by changingrotation speed of the blower 10 of the double-cavity heat exchanger 4.

Temperature in the refrigerating chamber 7 is additionally regulated byregulation of the rotation speed of the blower 9 in the air chiller 8.

Besides, additional regulation of temperature in the refrigeratingchamber 7 is performed by additional cooling of compressed air in thedouble-cavity heat exchanger 4 by installing Peltier thermoelectricmodules in that double-cavity heat exchanger, by cooling of compressedair in the double-cavity heat exchanger 4 by feeding water through thelatter, by regulation of the rotation speed of the electric motor 3, theshaft of which is coupled with the shaft 28 of the compressor 1 andcentrifugal expander 2.

The principle of operation of the air turbo-refrigerating plantaccording to FIGS. 2, 3 and 5 is implemented as follows.

The compressor 1 feeds compressed air into the first cavity of thedouble-cavity heat exchanger 4, in which compressed air is cooled withambient air supplied by the blower 10 via the second cavity of thedouble-cavity heat exchanger 4.

Then compressed air is cooled in the first cavity of the double-cavityheat-exchanging chiller 12 with air supplied through the said chillerfrom the centrifugal expander 2, and then compressed air is separatedfrom moisture in the second moisture separator 12.

Following which compressed air is cooled in the first cavity of therecuperator 5 with cold air supplied from the chiller 8 of therefrigerating chamber 7, after which compressed air is separated frommoisture in the moisture separator 6; then dried compressed air is fedinto the centrifugal expander 2 where air is cooled by way of expansionand transformation of its pressure energy into mechanical energy ofrotation of the wheels 23 and 24 of the centrifugal expander 2 and thecompressor 1, respectively.

Air cooled in the centrifugal expander 2 is separated from moisture inthe third moisture separator 14 and fed at low pressure achieved in thecentrifugal expander 2 via the second cavity of the heat-exchangingchiller 12 into the chiller 8 of the refrigerating chamber 7 in order toremove heat from the said chamber and cool it, while air heated in thechiller 8 is fed into the second cavity of the recuperator 5 for coolingof compressed air.

From the second cavity of the recuperator 5 air is fed to the inlet ofthe second compressor 17 which compresses air and feeds it into thefirst cavity of the second double-cavity heat exchanger 19, in whichcompressed air is cooled by feeding ambient air with the second blower20 via the second cavity of the second double-cavity heat exchanger 19,while from the first cavity of the second double-cavity heat exchanger19 air is fed into the compressor 1, with temperature in therefrigerating chamber 7 and cooling capacity of the airturbo-refrigerating plant being controlled by regulation of the rotationspeed of the blower 10 in the double-cavity heat exchanger 4.

Additional regulation of temperature in the refrigerating chamber 7shall be provided by regulation of the rotation speed of the blower 20in the second double-cavity heat exchanger 19, regulation of rotationspeed of the electric motor 18 in the second compressor 17, simultaneousregulation of the electric motor 18 in the second compressor 17, andregulation of the rotation speed of the blower 20 in the seconddouble-cavity heat exchanger 19 and the blower 9 in the chiller 8,additional cooling of the second double-cavity heat exchanger 19 usingPeltier thermoelectric modules, additional cooling in parallel of thefirst 4 and the second 19 double-cavity heat exchangers using Peltierthermoelectric modules, additional cooling of the second double-cavityheat exchanger 19 with water, additional cooling in parallel of thefirst 4 and second 19 of the double-cavity heat exchangers with water,regulation of the rotation speed of the blower 9 of the chiller 8,regulation of the rotation speed of the second electric motor 21, theshaft of which is coupled with the shaft of the compressor 1 and thecentrifugal expander 2.

The principle of operation of the air turbo-refrigerating plantaccording to FIGS. 4 and 5 is implemented as follows.

Compressed air is fed into the first cavity of the double-cavity heatexchanger 4 where compressed air is cooled with ambient air fed with theblower 10 via the second cavity of the double-cavity heat exchanger 4.

Then compressed air is cooled in the first cavity of the double-cavityheat-exchanging chiller 12 with air fed through the said chiller fromthe centrifugal expander 2, following which this compressed air isseparated from moisture in the second moisture separator 13.

Then compressed air is cooled in the recuperator 5 with cold air, fromthe chiller 8 of the refrigerating chamber 7, following which compressedair is separated from moisture is separated moisture in the moistureseparator 6, and then dried compressed air is fed into the centrifugalexpander 2 where it, by way of expansion and transformation of itspressure energy into mechanical energy of rotation of wheels 23 and 24of the centrifugal expander and compressor 1, is cooled and then aircooled in the centrifugal expander 2 is separated from moisture in thethird moisture separator 14, following which dried air is fed at reducedvia the second cavity of the double-cavity heat-exchanging chiller 12into the chiller 8 of the refrigerating chamber 7 for removal of heatfrom, and cooling, of the said chamber, following which air from thechiller 8 is fed into the second cavity of the recuperator 5 wherecompressed air is cooled, while from the second cavity of therecuperator 5 air is fed into the inlet of the compressor 1 whichcompresses air and feeds it into the second compressor 17, from whichadditionally compressed air is fed into the first cavity of the seconddouble-cavity heat exchanger 19, while in the latter heat exchangercompressed air is cooled by feeding ambient air through the secondcavity of the second double-cavity heat exchanger 19 with the secondblower 20, and from the first cavity of the second double-cavity heatexchanger 19 air if fed into the third compressor 22, from whichcompressed air is fed into the first cavity of the double-cavity heatexchanger 4.

Regulation of temperature in the refrigerating chamber 7 and coolingcapacity of the air turbo-refrigerating plant is performed by regulationof the rotation speed of the blower 10 of the double-cavity heatexchanger 4.

Additional regulation of temperature in the refrigerating chamber 7 isperformed by regulating the rotation speed of the blower 9 which feedsair in the refrigerating chamber 7 through the chiller 8, by additionalcooling of compressed air in the double-cavity heat exchanger 4, byinstalling in the latter Peltier thermoelectric modules, by additionalcooling of compressed air in the double-cavity heat exchanger 4 withwater run through this heat exchanger, by regulation of the rotationspeed of the electric motor 18, the shaft of which is coupled to theshaft of the second 18 and third 22 compressors, by regulation of therotation speed of the second electric engine 21, the shaft of which iscoupled to the shaft of the compressor 1 and the centrifugal expander 2.

INDUSTRIAL APPLICABILITY

This invention may be applied in air conditioning systems, refrigeratorsand other devices and installations where low temperature is to bemaintained.

1. An air turbo-refrigerating plant which contains a compressor directlycoupled to a centrifugal expander, electric motor with the shaft coupledto the shaft of a compressor and a centrifugal expander, a double-cavityheat exchanger, recuperator, moisture separator, refrigerating chamberwith a chiller and a blower, with inlet and outlet of the seconddouble-cavity heat exchanger opening to the atmosphere, where the inletof the latter is via a blower, and the compressor's inlet opens via itsvalve member to the atmosphere, characterized in that the plant isequipped with a double-cavity heat-exchanging chiller, and the secondand third moisture separators, with the compressor's outlet connected tothe first cavity of the double-cavity heat exchanger, the said firstcavity being connected to the first cavity of the double-cavityheat-exchanging chiller connected via the second moisture separator tothe first cavity of the recuperator, with the said cavity connected viathe first moisture separator to the inlet of the centrifugal expander,and the latter's outlet is connected via the third moisture separator tothe second cavity of the double-cavity heat-exchanging chiller, the saidsecond cavity connected to the chiller, and—through the latterchiller—to the second cavity of the recuperator, the said second cavitybeing connected to the compressor inlet.
 2. The plant which, accordingto claim 1, is characterized in that it is equipped with an air dryerpackage, the inlet of which opens to the atmosphere, and the outlet ofwhich—via the second valve member—to the compressor inlet.
 3. The plantwhich, according to claim 1 or 2, is characterized in that thedouble-cavity heat exchanger is equipped with Peltier thermoelectricmodules.
 4. The air turbo-refrigerating plant containing a compressordirectly coupled to a centrifugal expander, a double-cavity heatexchanger, recuperator, moisture separator, refrigerating chamber with achiller and a blower, where inlet and outlet of the second cavity of thedouble-cavity heat exchanger open to the atmosphere, and the outlet isvia the blower, the above plant characterized in that the plant isequipped with a double-cavity heat-exchanging chiller, the second andthird moisture separators, the second motor-driven compressor and thesecond double-cavity heat exchanger, with the compressor outletconnected to the first cavity of the double-cavity heat exchanger, thesaid first cavity being connected to the first cavity of thedouble-cavity heat-exchanging chiller, the said first cavity connectedvia the second moisture separator to the first recuperator cavityconnected via the first moisture separator to the centrifugal expander'sinlet, while the centrifugal expander's outlet is connected via thethird moisture separator to the second cavity of the heat-exchangingchiller, the said second cavity being connected to the chiller and, viathe chiller, to the second cavity of the recuperator, the latter secondcavity connected to the inlet of the second compressor, while the latteropens with its inlet via the valve member to the atmosphere and with theoutlet—via the first cavity of the second double-cavity heat exchangerconnected to the compressor inlet, and the inlet and outlet of thesecond double-cavity heat exchanger open to the atmosphere, with theinlet being connected via the second blower.
 5. The plant, according toclaim 4, being characterized in that it is equipped with the air dryerpackage, the latter opening via its inlet to the atmosphere, andconnected via it outlet to the inlet of the second compressor.
 6. Theplant, according to claim 4, being characterized in that it is equippedwith the second electric motor, the shaft of which coupled to the shaftof the compressor and centrifugal expander.
 7. The plant, according toany of claims 4-6, being characterized in that the double-cavity heatexchanger is equipped with Peltier thermoelectric modules.
 8. The airturbo-refrigerating plant containing the directly coupled compressor andcentrifugal expander, double-cavity heat exchanger, recuperator,moisture separator and refrigerating chamber with a chiller and ablower, with inlet and outlet of the second cavity of the double-cavityheat exchanger open to the atmosphere, while inlet is via the blower,being characterized that the plant is equipped with a double-cavityheat-exchanging chiller, second and third moisture separators, and thesecond and third compressors being directly coupled, electric motor, theshaft of which is coupled to the shaft of the second and thirdcompressors, and with the second double-cavity heat exchanger, with thecompressor inlet connected to the inlet of the second compressor whichis connected with its outlet via the first cavity of the seconddouble-cavity heat exchanger to inlet of the third compressor, theoutlet of which is connected via the first cavity of the double-cavityheat exchanger to the first cavity of the heat-exchanging chiller, thesaid chiller's cavity connected via the second moisture separator to thefirst cavity of the recuperator connected via the first moistureseparator to the outlet of the centrifugal expander, while the latterwith its outlet is connected to the second cavity of the heat-exchangingchiller, the latter cavity connected to the chiller and, via the latter,to the second cavity of the recuperator, the latter cavity beingconnected to the compressor inlet, with the latter's inlet opening tothe atmosphere via the valve member while the second cavity of thesecond double-cavity heat exchanger opens to the atmosphere on the sideof both the inlet and outlet, and on the side of the inlet—via thesecond blower.
 9. A plant, according to claim 8, being characterized inthat it is equipped with an air dryer package which opens via inlet tothe atmosphere and is connected with its outlet via the second valvemember to the compressor inlet.
 10. A plant, according to any of claims8 and 9, being characterized in that the first and second double-cavityheat exchangers are equipped with Peltier thermoelectric modules.
 11. Aplant, according to any of claims 8 to 10, being characterized in thatit is equipped with the second electric motor, the shaft of which iscoupled to the shaft of the compressor and centrifugal expander.
 12. Thecentrifugal expander containing directly coupled wheels of thecentrifugal expander and the compressor mounted on same shaft installedin the shell between gas-dynamic bearings, being characterized in thatan axial shaft stabilizer is installed in the shell opposite to theshaft end on the side of the compressor wheel clear of the laststationary magnet.
 13. The centrifugal expander, according to claim 12,being characterized in that in the axial shaft stabilizer a stationaryelectric magnet is installed.
 14. The centrifugal expander, according toclaim 13, being characterized in that the electric magnet includes ownmagnetic field strength regulator.
 15. The centrifugal expander,according to claim 12, characterized in that in the axial shaftstabilizer a stationary permanent magnet is installed.
 16. Thecentrifugal expander, according to claim 12, characterized in that itadditionally contains a permanent magnet installed on the shaft endopposite to the stationary magnet.
 17. The centrifugal expander,according to claim 12, characterized in that it is equipped with thesecond axial shaft stabilizer installed in the shell opposite to theshaft end on the side of the wheel of the centrifugal expander wheelclear of the second stationary magnet, with the second permanent magnetinstalled on the shaft end opposite to the second stationary magnet. 18.The centrifugal expander, according to claim 17, characterized in thatin the second axial shaft stabilizer a stationary n electric magnet isinstalled.
 19. The centrifugal expander, according to claim 18,characterized in that the electric magnet contains a magnetic fieldstrength regulator.
 20. The centrifugal expander, according to claim 17,characterized in that in the second axial shaft stabilizer a stationarypermanent magnet is installed.
 21. The principle of operation of the airturbo-refrigerating plant, according to any of claims 1-3, involvingsupply of compressed air with the compressor into the first cavity ofthe double-cavity heat exchanger in which compressed air is cooled withambient air fed with the blower via the second cavity of thedouble-cavity heat exchanger, following which compressed air is cooledin the recuperator with cold air fed supplied from the cooler of therefrigerating chamber, after which compressed air is separated frommoisture in the moisture separator and dried compressed air is fed intothe centrifugal expander, where air, by way of expansion andtransformation of its pressure energy into mechanical energy of rotationof wheels of the centrifugal expander and compressor is cooled and fedunder reduced pressure into the cooler of the refrigerating chamber forremoval of heat from, and cooling of, the chamber; from the cooler airis fed into the second cavity of the recuperator where compressed air iscooled, after which air is fed from the recuperator to the compressorinlet, characterized in that compressed air, before being fed in thefirst cavity of the recuperator, is cooled in the double-cavity heatexchanging chiller with air fed through it from the centrifugal expanderand is separated from moisture in the second moisture separator, and aircooled in the centrifugal expander, before it is fed via thedouble-cavity heat-exchanging chiller into the cooler of therefrigerating chamber, is separated from moisture in the third moistureseparator, with temperature in the refrigerating chamber and coolingcapacity of the air turbo-refrigerating plant being regulated bychanging rotation speed of the blower in the double-cavity heatexchanger.
 22. Principle of operation, according to claim 21,characterized in that temperature in the refrigerating chamber isadditionally regulated by changing the rotation speed of the blower inthe air cooler.
 23. The principle of operation, according to any ofclaims 21 and 22, characterized in that temperature in the refrigeratingchamber is additionally regulated by cooling of compressed air in thedouble-cavity heat exchanger by installing of Peltier thermoelectricmodules.
 24. The principle of operation, according to any of claims 21to 23, characterized in that temperature in the refrigerating chamber isadditionally regulated by cooling of compressed air in the double-cavityheat exchanger, by feeding water through the double-cavity heatexchanger.
 25. The principle of operation, according to any of claims 21to 24, being characterized in that temperature in the refrigeratingchamber is additionally regulated by changing rotation speed of theelectric motor directly coupled to the compressor and centrifugalexpander.
 26. The principle of operation, according to any of claims 4to 7, involving supply of compressed air into the first chamber of thedouble-chamber heat exchanger in which compressed air is cooled withambient air fed by the blower via the second chamber, after whichcompressed air is cooled in the recuperator with cold air from thecooler of the refrigerating chamber, following which compressed air isseparated from moisture in the moisture separator and dried compressedair is fed into the centrifugal expander where air, by way of expansionand transformation of its pressure energy into mechanical energy ofrotation of wheels of the centrifugal expander and compressor, and feedat reduced pressure into the cooler of the refrigerating chamber inorder to remove heat from the said chamber and cool it; from the chillerair is fed into the second chamber of the recuperator where compressedair is cooled, characterized in that compressed air, before being fedinto the first cavity of the recuperator, is cooled in the double-cavityheat-exchanging chiller with air fed through it from the centrifugalexpander and is separated from moisture in the second moistureseparator, air cooled in the centrifugal expander, before being fed viathe double-cavity heat-exchanging chiller into the cooler of therefrigerating chamber, is separated from moisture in the third moistureseparator, air from the second chamber of the recuperator air is fedinto the inlet of the second compressor which compresses air anddelivers it into the first chamber of the double-cavity heat exchanger,in the latter compressed air is cooled feeding ambient air via thesecond chamber of the second double-cavity heat exchanger with thesecond blower, while from the first chamber of the second double-cavityheat exchanger air is fed into the compressor, where temperature in therefrigerating chamber and cooling capacity of the airturbo-refrigerating plant is performed by regulation of rotation speedof the blower of the double-cavity heat exchanger.
 7. The principle ofoperation according to claim 26, characterized in that additionalregulation of temperature in the refrigerating chamber is performed byregulation of rotation speed of the blower of the second double-cavityheat exchanger.
 28. The principle of operation according to any ofclaims 26 and 27 characterized in that additional regulation oftemperature in the refrigerating chamber is performed by regulation ofrotation speed of the electric motor of the second compressor.
 29. Theprinciple of operation according to claim 26 characterized in thatadditional regulation of temperature in the refrigerating chamber andcooling capacity of the refrigerating plant is performed simultaneouslyby changing the rotation speed of the electric motor of the secondcompressor and changing rotation speed of the blower in the seconddouble-cavity heat exchanger and chiller blower.
 30. The principle ofoperation according to claim 26, characterized in that temperature inthe refrigerating chamber is additionally regulated by cooling of thesecond double-cavity heat exchanger with Peltier thermoelectric modules.31. The principle of operation according to claim 26, characterized inthat temperature in the refrigerating chamber is additionally regulatedby additional simultaneous cooling of the first and the seconddouble-cavity heat exchangers using Peltier thermoelectric modules. 32.The principle of operation according to claim 26, characterized in thattemperature in the refrigerating chamber is additionally regulated byadditional cooling of the second double-cavity heat exchanger withwater.
 33. The principle of operation according to claim 26,characterized in that temperature in the refrigerating chamber isadditionally regulated by additional simultaneous cooling of the firstand the second double-cavity heat exchangers with water.
 34. Theprinciple of operation according to claim 26, characterized in thattemperature in the refrigerating chamber is additionally regulated bychanging rotation speed of the chiller blower.
 35. The principle ofoperation according to claims 26, 32 to 34, characterized in thattemperature in the refrigerating chamber is additionally regulated bychanging rotation speed of the second electric motor, the shaft of whichis coupled to the shaft of the compressor and centrifugal expander. 36.The principle of operation of the air turbo-refrigerating plant,according to claim 8, involving supply of compressed air into the firstcavity of the double-cavity heat exchanger, in which compressed air iscooled with ambient air supplied with the blower via the second cavityof the double-cavity heat exchanger, following which compressed air iscooled in the recuperator with cold air fed from the cooler of therefrigerating chamber, following which compressed air is separated frommoisture in the moisture separator and dried compressed air is fed inthe centrifugal expander where it is cooled by way of expansion andtransformation of its pressure energy into mechanical energy of rotationof wheel of the centrifugal expander and compressor and fed underreduced pressure into the cooler of the refrigerating chamber for heatremoval from the latter and cooling, after which from the cooler air isfed into the second cavity of the recuperator where compressed air iscooled, characterized in that compressed air, before being fed into thefirst cavity of the recuperator, is cooled in the double-cavityheat-exchanging chiller with air fed via this chiller from thecentrifugal expander and is separated from moisture in the secondmoisture separator, after which air cooled in the centrifugal expander,before being fed via the double-cavity heat-exchanging chiller into thecooler of the refrigerating chamber, is separated from moisture in thethird moisture separator, from the second cavity of the recuperator airis fed into the inlet of the compressor which compresses air and feedsit into the second compressor, from which additionally compressed air isfed into the first cavity of the second double-cavity heat exchanger,while in the latter compressed air is cooled by feeding ambient air withthe second blower via the second cavity of the second double-cavity heatexchanger, and from the first cavity of the second double-cavity heatexchanger air is fed into the third compressor, from which compressedair is fed into the first cavity of the double-cavity heat exchanger,while regulation of temperature in the refrigerating chamber and coolingcapacity of the air turbo-refrigerating plant is performed by regulationof rotation speed of the blower of the double-cavity heat exchanger. 37.The principle of operation according to claim 36, characterized in thattemperature in the refrigerating chamber is additionally regulated byregulating rotation speed of the blower which feeds air into therefrigerating chamber through the cooler.
 38. The principle of operationaccording to any of claims 36 and 37, characterized in that temperaturein the refrigerating chamber is additionally regulated by additionalcooling of compressed air in the double-cavity heat exchanger byinstalling Peltier thermoelectric modules in that heat exchanger. 39.The principle of operation according to any of claims 36 and 37,characterized in that temperature in the refrigerating chamber isadditionally regulated by additional cooling of compressed air in thedouble-cavity heat exchanger with water fed through that heat exchanger.40. The principle of operation according to any of claims 36 and 37,characterized in that temperature in the refrigerating chamber andcooling capacity of the air turbo-refrigerating plant are regulated bychanging rotation speed of the blower in the second double-cavity heatexchanger.
 41. The principle of operation according to any of claims 36and 37, characterized in that additional regulation of temperature inthe refrigerating chamber is performed by additional cooling ofcompressed air in the second double-cavity heat exchanger by installingPeltier thermoelectric modules in that heat exchanger.
 42. The principleof operation according to any of claims 36 and 37, characterized in thatadditional regulation of temperature in the refrigerating chamber isperformed by additional cooling of compressed air in the seconddouble-cavity heat exchanger with water fed through that heat exchanger.43. The principle of operation according to any of claims 36 and 37,characterized in that additional regulation of cooling capacity andtemperature in the refrigerating chamber is performed by regulation ofrotation speed of the electric motor, the shaft of which is coupled tothe shaft of the second and third compressors.
 44. The principle ofoperation according to any of claims 36 and 37, characterized in thatadditional regulation of cooling capacity and temperature in therefrigerating chamber is performed by regulation of rotation speed ofthe second electric motor, the shaft of which is coupled to the shaft ofthe compressor and centrifugal expander.